In endometrial tissues, malignant change may be accompanied by a loss of hormone dependence which is, usually, reflected in a parallel loss of oestrogen and progesterone receptors (ER and PR). In this study, the steroid receptor status of 164 endometrial carcinomas was related to intratumoural angiogenesis and the apoptotic proteins bcl-2 and p53. Relationships to conventional histopathological features and patient survival were also sought. Immunohistochemistry was performed on formalin-fixed, paraffin-embedded tissues. The mean follow-up was 55 months (range 19-167 months). Specific nuclear staining for ER and PR was detected in 35% and 32% of endometrial carcinomas, respectively, and was very commonly co-expressed (P<0.0001). The failure of demonstrating a steroid receptor complement in endometrial neoplasms was, in general terms, an adverse prognostic sign. Thus, ER or PR loss was significantly associated with non-endometrioid carcinomas (ER P=0.01; PR P=0.004) and with deep myometrial invasion (ER P<0.0002), high intratumoural angiogenesis (PR P<0.01) and the absence of bcl-2 expression (PR P<0.005). There was a trend for patients with ER or simultaneous ER/PR expression to have an improved survival, but this association did not reach the level of statistical significance. In multivariate analysis (all stages), tumour cell type (endometrioid versus non-endometrioid carcinomas) and stage of disease were the only variables associated with prognosis (P=0.01 and P<0.0001, respectively), with tumour cell type retaining its independent prognostic value and within stage-I endometrial carcinomas (P=0.02). It is suggested that the loss of steroid hormone receptors in endometrial carcinomas is associated with a more aggressive phenotype and the switching-on of angiogenic pathways.